//
//  WBOAuthViewController.swift
//  传智微博
//
//  Created by wong on 17/1/8.
//  Copyright © 2017年 Canis. All rights reserved.
//

import UIKit
import SVProgressHUD
//通过 webView 加载新浪微博授权页面
class WBOAuthViewController: UIViewController {

    lazy var webView = UIWebView()
    
    override func loadView() {
        view = webView

        view.backgroundColor = UIColor.white
        
        //取消登录界面滚动视图 - 新浪微博的服务器，返回的授权页面默认是手机全屏
        webView.scrollView.isScrollEnabled = false
        
        //设置代理
        webView.delegate = self
        
        //设置导航栏
        title = "登录新浪微博"
        
        //导航栏按钮
        navigationItem.leftBarButtonItem = UIBarButtonItem(title: "返回" , target: self, action: #selector(close), isBack: true)
        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "自动填充", target: self, action: #selector(autoFill))
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
       //加载授权页面
        let urlString = "https://api.weibo.com/oauth2/authorize?client_id=\(WBAppKey)&redirect_uri=\(WBRedirectURI)"
        // 1> URL 确定要访问的资源
        guard let url = URL(string: urlString)else{
            
                return
            
        }
        // 2> 建立请求
        let request = URLRequest(url: url)
        
        // 3> 加载请求
        webView.loadRequest(request)
    }

   // MARK: - 监听方法
    func close(){
        SVProgressHUD.dismiss()
        dismiss(animated: true, completion: nil)
        
    }
    
    ///自动填充 - webView 的注入,直接通过 js 修改 '本地浏览器中' 缓存的页面内容
    ///点击登录按钮，执行submit() 将本地数据提交给服务器
    func autoFill(){
        //准备js 
        let js = "document.getElementById('userId').value = '13686879984';" + "document.getElementById('passwd').value = 'boyboy123';"
        
        //让webView执行 js
        webView.stringByEvaluatingJavaScript(from: js)
    }
    
}


extension WBOAuthViewController: UIWebViewDelegate{
    
    /// webView 将要加载请求
    ///
    /// - Parameters:
    ///   - webView: webView
    ///   - request: 要加载的请求
    ///   - navigationType: 导航类型
    /// - Returns: 是否加载request
    func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
        //1.如果请求地址包含 https://baidu.com 不加载页面  / 否则加载页面
        if request.url?.absoluteString.hasPrefix(WBRedirectURI) == false {
            return true
        }
        //print("加载请求 --- \(request.url?.absoluteURL)")
        
        //query 就是 URL 中 '?' 后面所有的部分
        //print("加载请求 --- \(request.url?.query)")
        //2.从 https://baidu.com 回调地址的查询字符串中查找 'code='
        //如果有，就说明授权成功，否则授权失败
        
        if request.url?.query?.hasPrefix("code=") == false{
            print("取消授权")
            close()
            return false
        }
        
        //3.从 query 字符串中取出授权码
        //代码走到此处，url中一定有查询字符串，并且包含 'code='
        let code = request.url?.query?.substring(from: "code=".endIndex) ?? ""
        
        print("获取授权码 - \(code)")
        
        //4.使用授权码获取[换取] AccessToken
        WBNetworkManager.shared.loadAccessToken(code: code){
            (isSuccess) in
            if !isSuccess
            {
                SVProgressHUD.showInfo(withStatus: "网络请求失败")
            }
            else{
               
                // 下一步通过通知发送登录成功的消息
                // 1> 发送通知 - 不关心有没有监听者
                NotificationCenter.default.post(name: NSNotification.Name(rawValue: WBUserLoginSuccessNotification), object: nil)
                
                // 2> 关闭窗口
                self.close()
            }
    
        }
        
        return false
    }
    
    func webViewDidStartLoad(_ webView: UIWebView) {
        SVProgressHUD.show()
    }
    func webViewDidFinishLoad(_ webView: UIWebView) {
        SVProgressHUD.dismiss()
    }
}
